SCEWN Design

Equipment

SCEWN is currently being constructed using low cost WISP equipment in order to demonstrate a working proof of concept. No long term commitment has been made nor is any intended to commit to a single technology, manufacturer or vendor. SCEWN is mission driven, not technology driven. We favor whichever materials and technologies attain community objectives for the best value.

• Current wireless links using 2.4 GHz and 5.8 GHz microwave bands under FCC Part 15 regulations.
• Current links range from 0.5 up to 11 miles using 18-24 dBi high gain directional antennas.
• Current radios employ modified 802.11 a,g, and n protocols. The minor modifications are optimizations needed for long range application.
• Most currently deployed radios are products by Ubiquity Networks, including the Bullet 2, Bullet M2, and in a few cases, the Nanostation 5. These radios were favored because they are the most affordable devices we could find that were tailored to long range communication. We also favor their compactness, ease of operation, and open architecture that greatly enhances our ability to customize them. They are hosted on a Linux based operating system.

Why not use 4.9 GHz public safety band?

The FCC has reserved the use of the 4.9 GHz band for public safety use. SCEWN would in all probability have little trouble obtaining sponsorship to enable the use of the 4.9 GHz band for this purpose. The band would be advantageous because of the lack of interference compared with the unlicensed general use bands. The disadvantage is a shortage of gear available for use on this band. It is more expensive and has fewer features, so there is a tradeoff between the lower noise vs the less capable equipment. For example, the 4.9 GHz supports only 802.11a. The 2.4 and 5.8 GHz gear supports 802.11n and MIMO. We have not yet made a real world assessment of the performance difference or tested any 4.9 GHz gear.

Have you considered using amateur radio microwave spectrum?

See this article at SVWUX.org.

Is SCEWN the only project of its kind?

No. Andrew Brown, deployment director of SCEWN prior to 11/2011 is endeavoring to create a commercially sustainable system based on the SCEWN prototype to be known as InfraLink.

Radio Amateurs interested in broadband communications are exploring various approaches to mesh networking.

• EMesh
• http://hsmm-mesh.org